Showing papers in "Autonomous Robots in 2007"

Development environments for autonomous mobile robots: A survey

Abstract: Robotic Development Environments (RDEs) have come to play an increasingly important role in robotics research in general, and for the development of architectures for mobile robots in particular. Yet, no systematic evaluation of available RDEs has been performed; establishing a comprehensive list of evaluation criteria targeted at robotics applications is desirable that can subsequently be used to compare their strengths and weaknesses. Moreover, there are no practical evaluations of the usability and impact of a large selection of RDEs that provides researchers with the information necessary to select an RDE most suited to their needs, nor identifies trends in RDE research that suggest directions for future RDE development. This survey addresses the above by selecting and describing nine open source, freely available RDEs for mobile robots, evaluating and comparing them from various points of view. First, based on previous work concerning agent systems, a conceptual framework of four broad categories is established, encompassing the characteristics and capabilities that an RDE supports. Then, a practical evaluation of RDE usability in designing, implementing, and executing robot architectures is presented. Finally, the impact of specific RDEs on the field of robotics is addressed by providing a list of published applications and research projects that give concrete examples of areas in which systems have been used. The comprehensive evaluation and comparison of the nine RDEs concludes with suggestions of how to use the results of this survey and a brief discussion of future trends in RDE design.

A comparison of line extraction algorithms using 2D range data for indoor mobile robotics

Abstract: This paper presents an experimental evaluation of different line extraction algorithms applied to 2D laser scans for indoor environments. Six popular algorithms in mobile robotics and computer vision are selected and tested. Real scan data collected from two office environments by using different platforms are used in the experiments in order to evaluate the algorithms. Several comparison criteria are proposed and discussed to highlight the advantages and drawbacks of each algorithm, including speed, complexity, correctness and precision. The results of the algorithms are compared with ground truth using standard statistical methods. An extended case study is performed to further evaluate the algorithms in a SLAM application.

Pre-collision safety strategies for human-robot interaction

Abstract: Safe planning and control is essential to bringing human-robot interaction into common experience. This paper presents an integrated human?robot interaction strategy that ensures the safety of the human participant through a coordinated suite of safety strategies that are selected and implemented to anticipate and respond to varying time horizons for potential hazards and varying expected levels of interaction with the user. The proposed planning and control strategies are based on explicit measures of danger during interaction. The level of danger is estimated based on factors influencing the impact force during a human-robot collision, such as the effective robot inertia, the relative velocity and the distance between the robot and the human. A second key requirement for improving safety is the ability of the robot to perceive its environment, and more specifically, human behavior and reaction to robot movements. This paper also proposes and demonstrates the use of human monitoring information based on vision and physiological sensors to further improve the safety of the human robot interaction. A methodology for integrating sensor-based information about the user's position and physiological reaction to the robot into medium and short-term safety strategies is presented. This methodology is verified through a series of experimental test cases where a human and an articulated robot respond to each other based on the human's physical and physiological behavior.

First steps toward natural human-like HRI

Abstract: Natural human-like human-robot interaction (NHL-HRI) requires the robot to be skilled both at recognizing and producing many subtle human behaviors, often taken for granted by humans. We suggest a rough division of these requirements for NHL-HRI into three classes of properties: (1) social behaviors, (2) goal-oriented cognition, and (3) robust intelligence, and present the novel DIARC architecture for complex affective robots for human-robot interaction, which aims to meet some of those requirements. We briefly describe the functional properties of DIARC and its implementation in our ADE system. Then we report results from human subject evaluations in the laboratory as well as our experiences with the robot running ADE at the 2005 AAAI Robot Competition in the Open Interaction Event and Robot Exhibition.

Simultaneous localization and odometry self calibration for mobile robot

Abstract: This paper presents both the theory and the experimental results of a method allowing simultaneous robot localization and odometry error estimation (both systematic and non-systematic) during the navigation. The estimation of the systematic components is carried out through an augmented Kalman filter, which estimates a state containing the robot configuration and the parameters characterizing the systematic component of the odometry error. It uses encoder readings as inputs and the readings from a laser range finder as observations. In this first filter, the non-systematic error is defined as constant and it is overestimated. Then, the estimation of the real non-systematic component is carried out through another Kalman filter, where the observations are obtained by two subsequent robot configurations provided by the previous augmented Kalman filter. There, the systematic parameters in the model are regularly updated with the values estimated by the first filter. The approach is theoretically developed for both the synchronous and the differential drive. A first validation is performed through very accurate simulations where both the drive systems are considered. Then, a series of experiments are carried out in an indoor environment by using a mobile platform with a differential drive.

Robotic smart house to assist people with movement disabilities

Abstract: This paper introduces a new robotic smart house, Intelligent Sweet Home, developed at KAIST in Korea, which is based on several robotic agents and aims at testing advanced concepts for independent living of the elderly and people with disabilities. The work focuses on technical solutions for human-friendly assistance in motion/mobility and advanced human-machine interfaces that provide simple control of all assistive robotic systems and home-installed appliances. The smart house concept includes an intelligent bed, intelligent wheelchair, and robotic hoist for effortless transfer of the user between bed and wheelchair. The design solutions comply with most of the users' requirements and suggestions collected by a special questionnaire survey of people with disabilities. The smart house responds to the user's commands as well as to the recognized intentions of the user. Various interfaces, based on hand gestures, voice, body movement, and posture, have been studied and tested. The paper describes the overall system structure and explains the design and functionality of some main system components.

A humanoid robot that pretends to listen to route guidance from a human

Abstract: This paper reports the findings for a humanoid robot that expresses its listening attitude and understanding to humans by effectively using its body properties in a route guidance situation. A human teaches a route to the robot, and the developed robot behaves similar to a human listener by utilizing both temporal and spatial cooperative behaviors to demonstrate that it is indeed listening to its human counterpart. The robot's software consists of many communicative units and rules for selecting appropriate communicative units. A communicative unit realizes a particular cooperative behavior such as eye-contact and nodding, found through previous research in HRI. The rules for selecting communicative units were retrieved through our preliminary experiments with a WOZ method. An experiment was conducted to verify the effectiveness of the robot, with the results revealing that a robot displaying cooperative behavior received the highest subjective evaluation, which is rather similar to a human listener. A detailed analysis showed that this evaluation was mainly due to body movements as well as utterances. On the other hand, subjects' utterance to the robot was encouraged by the robot's utterances but not by its body movements.

Distributed shape control of homogeneous swarms of autonomous underwater vehicles

Abstract: In this paper, we study large formations of underwater autonomous vehicles for the purposes of exploration and sampling the ocean surface. The formations or aggregates we consider are composed of up to hundreds of robots with the capability of forming various complex shapes dictated by the shape of the region to be explored, as well as special shapes suitable for migration. The shapes are determined through bathymetric maps and described with reduced-dimensional representation techniques. The approach we propose is that of breaking up the control and coordination strategy into two decoupled problems, i.e., partitioning the aggregate into two non-overlapping sets: its boundary and its interior. The boundary uses general theory of curve evolution to form shapes while the interior passively complies, using attraction-repulsion forces, to form a uniform distribution inside the boundary. This makes the problem much more tractable than previous methods. Decision making by individual robots is entirely based on local information, autonomous underwater vehicles, formation control, swarm control.

Behavioral overlays for non-verbal communication expression on a humanoid robot

Abstract: This research details the application of non-verbal communication display behaviors to an autonomous humanoid robot, including the use of proxemics, which to date has been seldom explored in the field of human-robot interaction In order to allow the robot to communicate information non-verbally while simultaneously fulfilling its existing instrumental behavior, a "behavioral overlay" model that encodes this data onto the robot's pre-existing motor expression is developed and presented The state of the robot's system of internal emotions and motivational drives is used as the principal data source for non-verbal expression, but in order for the robot to display this information in a natural and nuanced fashion, an additional para-emotional framework has been developed to support the individuality of the robot's interpersonal relationships with humans and of the robot itself An implementation on the Sony QRIO is described which overlays QRIO's existing EGO architecture and situated schema-based behaviors with a mechanism for communicating this framework through modalities that encompass posture, gesture and the management of interpersonal distance

Rescuing interfaces: A multi-year study of human-robot interaction at the AAAI Robot Rescue Competition

Abstract: This paper presents results from three years of studying human-robot interaction in the context of the AAAI Robot Rescue Competition. We discuss our study methodology, the competitors' systems and performance, and suggest ways to improve human-robot interaction in urban search and rescue (USAR) as well as other remote robot operations.

Socially distributed perception: GRACE plays social tag at AAAI 2005

Abstract: This paper presents a robot search task (social tag) that uses social interaction, in the form of asking for help, as an integral component of task completion. Socially distributed perception is defined as a robot's ability to augment its limited sensory capacities through social interaction. We describe the task of social tag and its implementation on the robot GRACE for the AAAI 2005 Mobile Robot Competition & Exhibition. We then discuss our observations and analyses of GRACE's performance as a situated interaction with conference participants. Our results suggest we were successful in promoting a form of social interaction that allowed people to help the robot achieve its goal. Furthermore, we found that different social uses of the physical space had an effect on the nature of the interaction. Finally, we discuss the implications of this design approach for effective and compelling human-robot interaction, considering its relationship to concepts such as dependency, mixed initiative, and socially distributed cognition.

Using a hand-drawn sketch to control a team of robots

Abstract: In this paper, we describe a prototype interface that facilitates the control of a mobile robot team by a single operator, using a sketch interface on a Tablet PC. The user draws a sketch map of the scene and includes the robots in approximate starting positions. Both path and target position commands are supported as well as editing capabilities. Sensor feedback from the robots is included in the display such that the sketch interface acts as a two-way communication device between the user and the robots. The paper also includes results of a usability study, in which users were asked to perform a series of tasks.

Guiding robots' behaviors using pheromone communication

Abstract: This paper describes an ongoing project to investigate the uses of pheromones as a means of communication in robotics. The particular example of pheromone communication considered here was inspired by queen bee pheromones that have a number of crucial functions in a bee colony, such as keeping together and stabilizing the colony. In the context of a robotic system, one of the proposed applications for robot pheromones is to allow a group of robots to be guided by a robot leader. The robot leader could release different chemicals to elicit a range of behaviors from other members of the group. A change of the operating temperature of tin oxide gas sensors has been implemented in order to differentiate different chemicals. This paper provides details of the robots used in the project and their behaviors. The sensors, especially the method of using the tin oxide gas sensors, the robot control algorithms and experimental results are presented. In this project, pheromones were used to trigger congregating behavior and light seeking in a group of robots.

Guidance of a mobile robot using an array of static cameras located in the environment

Abstract: This paper presents a new proposal for positioning and guiding mobile robots in indoor environments. The proposal is based on the information provided by static cameras located in the movement environment. This proposal falls within the scope of what are known as intelligent environments; in this case, the environment is provided with cameras that, once calibrated, allow the position of the robots to be obtained. Based on this information, control orders for the robots can be generated using a radio frequency link. In order to facilitate identification of the robots, even under extremely adverse ambient lighting conditions, a beacon consisting of four circular elements constructed from infrared diodes is mounted on board the robots. In order to identify the beacon, an edge detection process is carried out. This is followed by a process that, based on the algebraic distance, obtains the estimated ellipses associated with each element of the beacon. Once the beacon has been identified, the coordinates of the centroids for the elements that make up the beacon are obtained on the various image planes. Based on these coordinates, an algorithm is proposed that takes into account the standard deviation of the error produced in the various cameras in ascertaining the coordinates of the beacon's elements. An odometric system is also used in guidance that, in conjunction with a Kalman Filter, allows the position of the robot to be estimated during the time intervals required to process the visual information provided by the cameras.

The DARPA PerceptOR evaluation experiments

Abstract: This article describes the conduct of six evaluation experiments for the Perception for Off-Road Robotics program. Key distinctions of the testing methodology include conduct of the experiments by a group independent from the developers, unrehearsed experiments that provide little advance knowledge of the test courses, and blind experiments that do not allow the system operators to see the test courses until testing has completed. The article presents quantified, objective performance metrics for the systems evaluated. The basis for evaluation is 296 runs traveling 130 km in 110 hr. The results show significant progress over the course of the program, reducing the Emergency-Stops per kilometer by a factor of 22, reducing the uplink data volume per unit distance by a factor of 46 and the downlink data volume per unit distance by a factor of 3. At the end of Phase III, typical performance in desert terrain by the most reliable system achieved travel speed of 66 cm/s covering 90% of the distance in autonomous mode.

Analysis results and tools for the control of planar bipedal gaits using hybrid zero dynamics

Abstract: New analysis and tools are presented that extend the hybrid zero dynamics (HZD) framework for the control of planar bipedal walkers. Results include (i) analysis of walking on a slope, (ii) analysis of dynamic (decoupling matrix) singularities, and (iii) an alternative method for choosing virtual constraints. A key application of the new tools is the design of controllers that render a passive bipedal gait robust to disturbances without the use of full actuation--while still requiring zero control effort at steady-state. The new tools can also be used to design controllers for gaits having an arbitrary steady-state torque profile. Five examples are given that illustrate these and other results.

Human-robot cooperation control for installing heavy construction materials

Abstract: Previously, ASCI (Automation System for Curtain-wall Installation) which combined with a multi-DOF manipulator to a mini-excavator was developed and applied on construction site. As result, the operation by one operator and more intuitive operation method are proposed to improve ASCI's operation method which need one person with a remote joystick and another operating an excavator. The human-robot cooperative system can cope with various and untypical constructing environment through the real-time interacting with a human, robot and constructing environment simultaneously. The physical power of a robot system helps a human to handle heavy construction materials with relatively scaled-down load. Also, a human can feel and response the force reflected from robot end effecter acting with working environment. This paper presents the feasibility study regarding the application of the proposed human-robot cooperation control for construction robot through experiments on a 2DOF manipulator.

Visual homing in environments with anisotropic landmark distribution

Abstract: Gradient descent in image distances can lead a navigating agent to the goal location, but in environments with an anisotropic distribution of landmarks, gradient home vectors deviate from the true home direction. These deviations can be reduced by applying Newton's method to matched-filter descent in image distances (MFDID). Based on several image databases we demonstrate that the home vectors produced by the Newton-based MFDID method are usually closer to the true home direction than those obtained from the original MFDID method. The greater accuracy of Newton-MFDID home vectors in the vicinity of the goal location would allow a navigating agent to approach the goal on straighter trajectories, improve the results of triangulation procedures, and enhance a robot's ability to detect its arrival at a goal.

Vision-based motion planning for an autonomous motorcycle on ill-structured roads

Abstract: We report our development of a vision-based motion planning system for an autonomous motorcycle designed for desert terrain, where uniform road surface and lane markings are not present. The motion planning is based on a vision vector space (V2-Space), which is a unitary vector set that represents local collision-free directions in the image coordinate system. The V2-Space is constructed by extracting the vectors based on the similarity of adjacent pixels, which captures both the color information and the directional information from prior vehicle tire tracks and pedestrian footsteps. We report how the V2-Space is constructed to reduce the impact of varying lighting conditions in outdoor environments. We also show how the V2-Space can be used to incorporate vehicle kinematic, dynamic, and time-delay constraints in motion planning to fit the highly dynamic requirements of the motorcycle. The combined algorithm of the V2-Space construction and the motion planning runs in O(n) time, where n is the number of pixels in the captured image. Experiments show that our algorithm outputs correct robot motion commands more than 90% of the time.

Environment adaptation of a new staircase-climbing wheelchair

Abstract: This paper describes the mechanical devices conforming a novel wheelchair prototype capable of climbing staircases. The key feature of the mechanical design is the use of two decoupled mechanisms in each axle, one to negotiate steps, and the other to position the axle with respect to the chair to accommodate the overall slope. This design simplifies the control task substantially. Kinematic models are necessary to describe the behavior of the system and to control the actuated degrees of freedom of the wheelchair to ensure the passenger's comfort. The choice of a good climbing strategy simplifies the control and decreases the power consumption of the wheelchair. In particular, we demonstrate that if the movement of the wheelchair has the same slope as the racks or the same slope as the terrain that supports the wheel axles (depending on the configuration mechanism), control is easier and power consumption is less. Experimental results are reported which show the behavior of the prototype as it moves over different situations: (a) ascending a single step of different heights using different climbing strategies; and (b) climbing a staircase using an appropriate climbing strategy that simplifies the control and reduces the power consumption of the wheelchair.

Linear estimation of the physical odometric parameters for differential-drive mobile robots

Abstract: In this paper a calibration technique aimed at identifying the odometric parameters of differential-drive mobile robots is proposed. The algorithm is based on two successive least-squares estimations based on the continuous-time kinematic equations of motion; the time-discretization error, thus, is avoided. The use of the least-squares technique is made possible by working on a linear mapping between the unknowns and the measurements and is not the result of a linearization. Another advantage of the proposed technique is that no specific path is required. The basic technique makes use of video-camera measurements and absolute position readings of the wheels' encoders; the use of different sensors and measurements of the wheels velocities is also discussed. Experimental results with a mobile robot Khepera II confirm the effectiveness of the proposed technique.

Adaptive behavior in turning of an oscillator-driven biped robot

Abstract: This paper concentrates on a biped robot's turning behavior that consists of straight and curved walking and the transition between these two patterns. We investigate how a robot achieves adaptive walking during such turning by focusing on rhythm control and propose a locomotion control system that generates robot motions by rhythmic signals from internal oscillators and modulates signal generation based on touch sensor signals. First, we verify that the robot attains limit cycles of straight and curved walking by numerical simulations and hardware experiments. Second, we examine the transition between these walking patterns based on the basin of attraction of the limit cycles in numerical simulations. Finally, we verify whether the robot actually accomplishes transition and turning by hardware experiments. This paper clarifies that the robot establishes such turning motions by adequate modulation of walking rhythm and phase through interactions between the dynamics of its mechanical system, oscillators, and environment.

Safe and effective navigation of autonomous robots in hazardous environments

Abstract: The development of autonomous mobile machines to perform useful tasks in real work environments is currently being impeded by concerns over effectiveness, commercial viability and, above all, safety. This paper introduces a case study of a robotic excavator to explore a series of issues around system development, navigation in unstructured environments, autonomous decision making and changing the behaviour of autonomous machines to suit the prevailing demands of users. The adoption of the Real-Time Control Systems (RCS) architecture (Albus, 1991) is proposed as a universal framework for the development of intelligent systems. In addition it is explained how the use of Partially Observable Markov Decision Processes (POMDP) (Kaelbling et al., 1998) can form the basis of decision making in the face of uncertainty and how the technique can be effectively incorporated into the RCS architecture. Particular emphasis is placed on ensuring that the resulting behaviour is both task effective and adequately safe, and it is recognised that these two objectives may be in opposition and that the desired relative balance between them may change. The concept of an autonomous system having "values" is introduced through the use of utility theory. Limited simulation results of experiments are reported which demonstrate that these techniques can create intelligent systems capable of modifying their behaviour to exhibit either `safety conscious' or `task achieving' personalities.

Development of the curtain wall installation robot: Performance and efficiency tests at a construction site

Abstract: The development of automation in construction has been restricted by the variety of construction materials used, variable circumstances, and difficulties in the quantitative management of the construction process. Curtain wall, however, can be considered a relatively standard material compared to other construction materials. In this study, we analyze the current process of curtain wall installation and investigate the potential of an automated system combining a commercial excavator and a 3-DOF manipulator. This automated system has the adaptations necessary to work with any type of commercialized excavator. Therefore, workers need to transfer only the 3-DOF manipulator portion of the system when they move to other construction sites. This paper investigates experimental trials involving the proposed system at construction sites to determine its performance, working time, and efficiency. Results from this study were analyzed and further research options outlined.

Spartacus attending the 2005 AAAI conference

Abstract: Spartacus is our robot entry in the 2005 AAAI Mobile Robot Challenge, making a robot attend the National Conference on Artificial Intelligence. Designing robots that are capable of interacting with humans in real-life settings can be considered the ultimate challenge when it comes to intelligent autonomous systems. One key issue is the integration of multiple modalities (e.g., mobility, physical structure, navigation, vision, audition, dialogue, reasoning). Such integration increases the diversity and also the complexity of interactions the robot can generate. It also makes it difficult to monitor how such increased capabilities are used in unconstrained conditions, whether it is done while the robot is in operation of afterwards. This paper reports solutions and findings resulting from our hardware, software and decisional integration work on Spartacus. It also outlines perspectives in making intelligent and interaction capabilities evolve for autonomous robots.

Locating sensor nodes on construction projects

Abstract: Localization of randomly distributed wireless sensor nodes is a significant and fundamental problem in a broad range of emerging civil engineering applications. Densely deployed in physical environments, they are envisioned to form ad hoc communication networks and provide sensed data without relying on a fixed communications infrastructure. To establish ad hoc communication networks among wireless sensor nodes, it is useful and sometimes necessary to determine sensors' positions in static and dynamic sensor arrays. As well, the location of sensor nodes becomes of immediate use if construction resources, such as materials and components, are to be tracked. Tracking the location of construction resources enables effortless progress monitoring and supports real-time construction state sensing. This paper compares several models for localizing RFID nodes on construction job sites. They range from those based on triangulation with reference to transmission space maps, to roving RFID reader and tag systems using multiple proximity constraints, to approaches for processing uncertainty and imprecision in proximity measurements. They are compared qualitatively on the basis of cost, flexibility, scalability, computational complexity, ability to manage uncertainty and imprecision, and ability to handle dynamic sensor arrays. Results of field experiments and simulations are also presented where applicable.

Development of the multi-functional indoor service robot PSR systems

Abstract: This paper discusses the development of the multi-functional indoor service robot PSR (Public Service Robots) systems. We have built three versions of PSR systems, which are the mobile manipulator PSR-1 and PSR-2, and the guide robot Jinny. The PSR robots successfully accomplished four target service tasks including a delivery, a patrol, a guide, and a floor cleaning task. These applications were defined from our investigation on service requirements of various indoor public environments. This paper shows how mobile-manipulator typed service robots were developed towards intelligent agents in a real environment. We identified system integration, multi-functionality, and autonomy considering environmental uncertainties as key research issues. Our research focused on solving these issues, and the solutions can be considered as the distinct features of our systems. Several key technologies were developed to satisfy technological consistency through the proposed integration scheme.

Improving walking-robot performances by optimizing leg distribution

Abstract: Walking-robot technology has already achieved an important stage of development, as demonstrated in a few real applications. However, walking robots still need further improvement if they are to compete with traditional vehicles. A potential improvement could be made through optimization at design time. A better distribution of the legs around a robot's body can help decrease actuator size in the design procedure and reduce power consumption during walking as well, which is of vital importance in autonomous robots. This paper, thus, presents a method focused on the distribution of legs around the body to decrease maximum foot forces against the ground, which play heavily in determining robot shape and actuator size. Some experiments have been performed with the SILO6 walking robot to validate the theoretical results.

NIST research in autonomous construction

Abstract: The National Institute of Standards and Technology Construction Metrology and Automation Group is conducting ongoing research to provide standards, methodologies, and performance metrics that will assist the development of advanced systems to automate construction tasks. Initial research in this project, entitled "Performance of Innovative Technologies for Automated Construction," has focused on autonomous large-scale pick-and-place operations using the assembly of structural steel as a test operation. An Automated Construction Testbed (ACT) is under development to research advanced concepts in crane automation, site metrology, laser-based 3D imaging, construction object identification and tracking, sensor-based data exchange, site status visualization, and design data integration for autonomous system planning. This paper provides an overview of this research effort.

Metric embedding of view-graphs

Abstract: Most recent robotic systems, capable of exploring unknown environments, use topological structures (graphs) as a spatial representation Localization can be done by deriving an estimate of the global pose from landmark information In this case navigation is tightly coupled to metric knowledge, and hence the derived control method is mainly pose-based Alternative to continuous metric localization, it is also possible to base localization methods on weaker constraints, eg the similarity between images capturing the appearance of places or landmarks In this case navigation can be controlled by a homing algorithm Similarity based localization can be scaled to continuous metric localization by adding additional constraints, such as alignment of depth estimates We present a method to scale a similarity based navigation system (the view-graph-model) to continuous metric localization Instead of changing the landmark model, we embed the graph into the three dimensional pose space Therefore, recalibration of the path integrator is only possible at discrete locations in the environment The navigation behavior of the robot is controlled by a homing algorithm which combines three local navigation capabilities, obstacle avoidance, path integration, and scene based homing This homing scheme allows automated adaptation to the environment It is further used to compensate for path integration errors, and therefore allows to derive globally consistent pose estimates based on "weak" metric knowledge, ie knowledge solely derived from odometry The system performance is tested with a robotic setup and with a simulated agent which explores a large, open, and cluttered environment